Method oe steam-heating



J. A. SERRELL.

METHOD OF STEAM HEATING.

APPLICATION FILED NOV. 12. 1915 Patehfed May 20, 1919.

INVENTOR ATTORNEY WITNESSES JOHN A. SERRELL, OF NORTH PLAINFIELD, NEW JERSEY.

METHOD OF STEAM-HEATING.

Specification of Letters Patent.

Patented May 20, 1919.

Original application filed January 7, 1910, Serial No. 536,894. Divided and this application filed November 12, 1915. Serial No. 60,997.

To all whom it may concern:

Be it known that I, JOHN A. SERRELL, a citizen of the United States, and resident of North Plainfield, county of Somerset, and State of New Jersey, have invented an Improvement in Methods of Steam-Heating, of which the following is a specification.

The object of my invention is'to provide a system of steam circulation in which there shall be maintained automatically a constant predetermined difference in pressure between the supply and return sides'of the system with respect to the radiators, whereby a proper circulation of steam is insured and the radiators will be efiiciently operated as heaters.

This application is a division of my application Serial Number 536,894, filed January 7, 1910, which eventuated in Letters Patent No. 1,152,560, dated September 7, 1915, said Letters Patent being issued for apparatus such as herein disclosed and as suitable types in which to practise my improved method of steam heating.

My invention depends upon the following requirements, namely: .the provision of means by which the difference in pressure in the boiler and the main return will not become great enough to force the water out of the boiler into the return system beyond what would be considered a good working condition; provision for causing the condensation from the heating system to flow continuously into the higher pressure in the boiler with assistance of a permissible water column in the return line; provision for insuring a pressure condition in the return system, at the same time forcing the air out of the system while preventing the escape of'steam therefrom; and provision of means for preventing any flow of air into the return system when the pressure therein is less than that of the atmosphere.

My invention consists of the method embodying in the operation the characteristic features above specified, and which method is fully described hereinafter and more specifically pointed out in the claims; and my invention will be better understood by reference to the drawings, in which Figure 1 is a diagrammatic illustration of a steam heating system adapted for use with the practice of my invention and showing part of the apparatus in section; Fig. 2 is an enlarged view of a portion of the appaleading from the boiler 5 in the basement,

and 4 is the return pipe for delivering the Water of condensation, and preferably the air, into a receiver 8 in the basement and from which the Water passes by gravity through a pipe 9 to the lower part of the boiler 5. The steam is supplied to the radiators from this supply pipe 3 through suitable control Valves 6 by which the amount of steam delivered to the radiators may be regulated.

7 represents automatic return valves or traps designed for permitting the free passage-of water and air from the radiators, but restricting the escape of steam. 'These automatic valves 7 maybe of any suitable construct-ion, being such 'for example as are in general use on vacuum or other systems of steam heating. The receiver 8 receives the water of condensation from the return pipe 4 and at the water level the said receiver is preferably of large area so as to receive considerable Water without varying the level of the surface therein beyond a moderate amount. Assuming that the level shown in Fig. l in the receiver 8 is the normal level, it will be seen that this level is above the normal level in the boiler a distance indicated by w, and this equals the column of water which is supported in the receiver bythe superior pressure 'in the boiler 5 and the supply pipe 3 over that which exists in the return pipe 4 and the receiver 8. Whenever the water in the receiver rises above the level indicated, it would automatically overcome the pressure of the boiler and the water would flow through the pipe 9 into the boiler until the proper normal level was again restored.

10 is a steam pipe leading from the supply pipe or, in any other manner, leading from the boiler 5, and said pipe 10 is provided on its end with a valve 11 within the receiver 8 for admitting steam into the receiver whenever the pressure in the boiler becomes abnormally high relative to the pressure in the receiver. This valve 11 is automatically operated by a float 17, whose action is dependent upon the level of the water within the receiver 8. The air which is received in the receiver 8 is permitted to be blown out through an automatic valve 15, which is also operated by the float 17. The air which passes through the valve 15 escapes by a pipe 15 from the receiver; thence passes through a check valve 18 and by a discharge pipe 19 through a water seal 20 to the escape pipe 21 leading to the atmos-, phere. The pipe 21 also acts as an overflow for the water seal 20. In case there is no lid used to the water seal, as shown in Fig. 3, then the air will not be required to pass through the pipe 21, and said pipe will merely act as an overflow pipe. The pipe 19 has a considerable drop so as to act as a resistance to the entrance of air, and in case of a vacuum within the receiver 8, to avoid driving the water out of the seal 20 into the receiver. If the check valve 18 is made sufiicient-ly air tight to prevent the passage of air, then the \vaterseal 20 may be omitted. Likewise, it is evident that if desired the water seal may be relied upon without the use of the check valve. The valves 11 and 15 are connected so as to be successively operated by the float 17, and these connections will be better understood by reference to Fig. 2. The valve piece of valve 11 is operated by a lever 12, and the valve piece of the air relief valve 15 is operated by a lever 1-1. The free ends of the levers 12 and 11 are connected by a link 13 which is jointed at or near its middle to the upper end of the rod 16 which is secured at its bottom to the float 17. Assuming that in Fig. 2 there is the normal static head desired and with valve 15 open and valve 11 closed, it will be understood that, should the water level rise farther in the receiver 8, it will be because thereis an abnormally higher pressure in the boiler. making the distance a: between the actual level in the receiver 8 and the normal'level in the boiler 5 greater than it sliOLlld be. \l'hen the float rises, it is with the object of increasing the pressure in the receiver and the return line 1. to reduce this differential in pressure so that it will equal the predetermined difference correspoiuling to the column of water. As the float rises, the first action is to oscillate the link 13 about the end of the lever 12 with the result that the valve 15 is closed to shut oti' the escape to the atn'iosphere. This action takes place because the lever 12 is weighted at 21, and consequently does not lift until the lever 1+ comes to a stop when the valve is closed. \Yben the valve 1.3 is closed, the further rising of the float 17 causes the link 1?, to lift the free end of the lever 12, and to open the steam valve 11 for the purpose of admitting steam from the boiler into the receiver Sto increase the pressure in said receiver. In this way the normal difi'erence in pressures between the supply and return sides of the system is maintained irrespective of the variations in pressure in the boiler and the supply pipe. \Vhen the steam is discharged through the valve 11 into the receiver, it may be delivered from a nozzle 23 opening through a surrounding port 22 into which the returns 1 discharge and in this way constitute an ejector which assists in discharging the water of condensation and air from the return pipe into the receiver. This refinement of the apparatus may be omitted, if desired.

As soon as the pressure in the receiver 8 reaches a proper pressurerelatively to the pressure in the boiler and supply mains which will insure the maintenance of the predetermined permissible column or static head 00, the valves 11 and 15 are again operated, but in the reverse order. The steam is in this manner shut off from the receiver and then the air valve 15 is opened to allow the escape of the air, the same passing upward through the pipe 15*, and thence through the check valve 18 and finally through the water seal 20. These devices operate automatically to maintain a pressureabove the atmosphere within the system and a differential pressure within the supply and return pipes which may equal a pressure up to that of the permissible static head. When operating at or below atmospheric pressure and until there is a greater difference in pressure between the supply and return than the permissible static head, the valve 15 will be open and the valve 11 shut. In this position of the valves the air will vent itself through the check valve and water seal whenever the pressure in the return is greater than atmospheric pressureplusthe resistance of the check and water seal. lVhen the pressure in the boiler rises above that in the receiver or separating tank sufiiciently to force the water back into the said receiver to the limit of the permissible static head, it acts on the float 1T, first closing the air vent valve 15, and if the accumulated pressure in the receiver is not sutlicient to hold or decrease the water level line and the water vstill continues to rise, the float will open the valve 11 and admit steam to the receiver in suflicient quantity, which, in connection with the permissible static head .1, balances the pressure in the boiler.

liy the principles involved in my improv d apparatus, I am enabled to establish a maximum differential between the steam' supply and the condensation return of a heating system by merely shutting'the air vent and then admitting pressure from the boiler above the pressure of the static column or permissible head, or in case a thermostatic valve 15 is used in place 01 the valve 15 as the means for permitting the escape of air (see Fig. 3), then by the automatic control of the steam inlet alone under the influence of the float. In this latter case the air and gases would be continuously vented when running under pressure above that of the static head and consequently, the

as in Fig. 1. In this case, inpl'ace of the receiver 8 of Fig. 1, a smaller receiver 8 is employed, which receives the water of con-' densation from the return pipe 4 and delivers the water of condensation to the boiler by a pipe 9. The normal level in the receiver' 8 is above the normal level of the water in the boiler by an amount equal toa static head indicated by w, as in the case of Fig. 1. The air from the receiver 8" is shown as vented through a check valve 18,

a thermostatic valve-'15", and a water seal 20 into which the air pipe 19 dip's,and said water seal may be provided with an overflow 21 as in the case of Fig. 1. In place of a float and valve 11 operated'thereby for controlling thesupply ofsteam fromv the boiler and supply pipe to the receiver and return pipe of the system, as illustrated in Fi 1, I may employ an ordinary reducing val ve of any suitable construction, as indicated at 11, said valve being arranged in the pipe 10 and preferably outside of the receiver 8 A suitable construction of reducing valve is shown in Fig.4 in which the steam passing through the pipe 10 is con trolled by a balanced valve 26 which is controlled by a diaphragm 27 actuated by steam pressure in the chamber 28 which is in communication with the pipe leading from the boiler, and said pressure counterbalanced by a counterbalance lever 29 having weights 30 and steam pressure above the diaphragm from the receiver side. By adjusting the weights, the pressure reducing valve may be caused to open whenever the pressure in the pipe 10 leading from the boiler teaches an excessive pressure above that predetermined by the adjustment of the weight 30 and pressure in the receiver. This reducing valve may be adjusted so as to maintain a certain differential in pressure between the pressure in the pipe 10 and in the receiver 8, so that should the pressure in the boiler rise, a correspondingly increased pressure will be admitted to the receiver 8 to counterbalance what would otherwise be an abnormal static head, and thereby maintain the permissible static head 09 unchanged and cause the radiators to be operatedunder a predetermined differential in pressure between the supply and return pipes of the system. In the construction shown in Fig.3.

the apparatus will operate, perhaps more uniformly than in the apparatus shown in Fig. 1, because the reducing valve 11 automatically operates under the influence of the increasing pressure of the: boiler and without the necessity of the level of the water in the reservoir directly acting to induce the regulation.

In the operation of this system, when the steam pressure generated in the boiler rises above that of the atmosphere it will force the air out of the supply pipes, radiators and return line, thence through the check valve, thermostatic valve and water'seal to the atmosphere, and fill the space from which the air has been displaced by steam.

If the steam be generated so rapidly that the pressure in the boiler sufliciently to force the water back through pipe 9 and receiver 8* andthreatens to fill the air vent,

the reducing valvell responds and admits the steam from the boiler to the receiver'S by the nozzle 25 therein, in sufficient quantity to increase the pressure in the receiver and return pipes, to such an extent as to holdthe water'linein the receiver 8 below the line of the airvent. When steam reaches the thermostatic valve, it will close and remain closed until either an accumulation of air occurs, or the pressure in the main return drops below the pressure of the atmosphere. In. this latter case, the check valve 18 and the water sea-120 will prevent passage of air into the system and it may continue to operate with a substantially constantly difi'erential below atmospheric pressure. While I have shown the water pan or seal 20 close to the-thermostatic valve 15", it isto be understood that it may be placed as low down as desired so as to get any length of pipe 19 required to act as a water column in case a material vacuum were produced in the system. If this column 19 could be made sufficiently long, the check valve 18,might be dispensed with, or if the check valve were sufficiently tight, the barometric column 19 and water seal 20 might be dispensed with. In generahthe apparatus on the air vent of the system are mere refinements, and neither of the several parts need be considered as essential. A safety valve 5 may be employed on the steam mainleading from the boiler to relieve an abnormal pressure should it occur from any derangement of the apparatus.

A heating system arranged as shown would circulate and returnits condensation to the boiler with a force equal to the permissible static head w whetherthe boiler pressure were considerably higher than atmospheric pressure or below atmospheric pressure, provided there were no leaks and pressure above atmosphere be first generated to force'out the air.

The advantage in my improved method of steam heating lies in the economy of being able to store up the steam caused by fluctuations in the firing of the boiler and also in being able to carry a pressure proportional to the outside temperature, rather than being limited to a pressure so near atmospheric pressure, that there will be no danger of blocking the returns and causing water hammer, or what may be considered a worse evil, forcing the boiler water out through the vent pipe.

In supplying steam in measured quantities to my improved system less than necessary to completely fill the individual radiators to operate them on what is'known as modulation, the quantity of steam admitted through the limited orifice of the modulation or supply valve on the radiator will remain constant under varying initial pressures because the initial and terminal pressures, namely those in the supply and return sides of the system, will remain at a substantially constant difierence; and for this reason, the system operates as a modulation system irrespective of varying initial boiler pressures.

I have shown apparatus for the practice of my improved method in forms which are suitable for commercial use at pressures above or below: atmosphere pressure, and while I prefer the construction shown as a means for practising my improved method, I do not restrict myself thereto, as they may be modified in various ways for use without causing a departure from the spirit of the invention.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is a 1. The herein described method of circulating steam for heating purposes, which consists in supplying steam to the radiators or coils of the system and withdrawing the water of condensation and air therefrom under a predetermined differential pressure while restricting the passage of steam from the radiators or coils, returning the water of condensation to the source of steam supply under a predetermined static head, and compensating for any increase in pressure in the source of steam supply by'automatically admitting steam in regulated quantities to the return side of the system without passing through the radiators or coils to maintain the static head substantially constant.

2. The herein described method of cireoeaoe culating steam for heating purposes, which consists in supplying steam to the radiators or coils of the system and withdrawing the water of condensation and air therefrom under a predetermined differential pressure while restricting the passage of steam from the radiators or coils, returning the water of condensation to the source of steam supply under a predetermined static head, compensating for any increase in pressure in the source of steam supply by automatically admitting steam in regulated quantities to the return side of the system without passing through the radiators or coils to maintain the static head substantially constant, and automatically removing the air from the system during the maintenance of the static head.

3. The herein described method of circulating steam for heating purposes, which consists in supplying steam from a source of steam supply to the radiators or coils of the system andwithdrawing the water of condensation and air therefrom while restricting the escape of steam, said operation taking place under a predetermined differential pressure between the supply and return sides of the radiators or coils, returning the water of condensation to the source of steam I supply under a predetermined statichead, compensating for any increase in pressure in the source of steam supply by automatically admitting steam in regulated quantities to the return side ofthe system without passing through the radiators or 100 coils to maintain the static head substantially constant, removing the air from the system while restricting the escape of steam therefrom during the maintenance of. the static head, and regulating the supply of 105 steam to the radiators or coils independently of the pressure conditions in the returns.

4. The herein described method of circulating steam for heating purposeswhich consists in supplying steam from a boiler to the radiators under pressure. automatically discharging the waterand air from the radiators into the returns and returning the Water of condensation under a pressure while restricting the escape of steam fromthe radiators, delivering the water of con densation to the boiler under a predetermined admissable static head, and maintaining the static headsubstantially constant under the control of the differential pressure between the source of steam and the return side of the system and independently of the pres,-

turning the water of condensation to the boiler under a predetermined static head, automatically removing the air from the return side of the system, and automatically causing the pressure in the return side of diators into the return side of the system,

maintaining a statichead in the return side of the system the lower part of which is affected by the .steam pressure of the boiler with which it communicates and the upper part of which is affected by' the pressure in the return side of the system, delivering the water from the return side of the system to the static head and into the boiler under the pressure of the static head supplemented by the pressure in the return'side of the system, causing the accumulations of air from the return side of the system to be discharged into the atmosphere, and controlling the pressure in the return side of the system by supplying regulated quantities of steam from the supply side of the system or boiler directly into the return side under the control of the difference in relative pressures -in the boiler and return side of the system and independent of the pressures in the radiators whenever the static head in the return side of the system becomes greater than that predetermined as the normal static head.

7. The herein described method of circulating steam for heating purposes, consisting in supplying steam from a source of steam generation to heating and condensing units and returning the condensation therefrom to the steam generator, permitting the escape of air from the return portion of the system and restricting the escape thereof whenever the difference in pressure between the supply and return portions of the system exceeds that predetermined'as a maximum, and keeping the differential within the predetermined maximum by the automatic admission of pressure from the supply side in measured'quantity whenever the predetermined difference would otherwise be exceeded, said admission of pressure independent of the pressures in the heating and condensing units, whereby the difference in pres.,ures between the supply and return sides of the system is prevented from exceeding the certain predetermined limits.

8. The herein described method of circulating steam for heating purposes, consisting in supplying steam from a source of steam generation to heating and condensing units and returning the condensation therefrom to the steam generator, permitting the escape of air from the return portion of the system and restricting the escape thereof whenever the difference in pressure between the supply and return portions of the system exceeds that predetermined as a maximum, and keeping the differential within the predetermined maximum by the automatic admission of pressure from the supply side of the system in measured quantityto the return side of the system and independent of the pressures in ,the heating and condensing units Whenever the predetermined difference would otherwise be ex ceeded, whereby the difference in pressures between the supply and return sides of the system is prevented from exceeding the certain predetermined limits.

9. The herein described method of circulating steam for heating purposes, which consists in supplying steam to radiators or coils of the system and causing the water and air to flow therefrom .into the return side of the system while restricting the escape of steam from the radiators or coils, said operation taking place within a predetermined d-ifferential pressure between the supply and return pipes respectively on opposite sides 'of theradiators or coils, returning the water of condensation to the source-of steam supply under a static head which shall not exceed the predetermined difi erential pressure, compensating for any increase in the pressure in the source of steam supply by admitting steam in regulated quantities'to the return side of the system above the static water columnwithout passing through the radiators or coils to prevent the static head in the return side exceeding the predetermined differential pressure, removing the air from the system 'while restrictin the escape of steam there- JOHN A." SERRELL.

Witnesses:

R. M. HUNTER, FLORENCE DEACON. 

